Member postings for Neil Wyatt

Standard metric sets have the first and second taps slightly undersize. I have both types and the undersize ones make tapping at large sizes or in tough materials much easier/less stressful, but as Jason says it does mean you have to make multiple passes. They are also handy for making small expanding mandrels.

For a jig, better to use dowels, hardened silver steel pins or even just plain bms pins for a temporary jig.

Neil

My inverter and motor are both set up for monitoring of motor temperature, but neither manual completely explains it

I'd quite like to enable monitoring of the winding temperature.

I have a Tec motor and in the control box two wires are brought out to a choc block. The manual hints (but does not confirm) that the motor may have a PT100 sensor.

Their website suggests this is actually 3 sensors.

It's about 20 degrees in here and the 324 ohm reading is about right for three PT100 sensors in series.

All well and good.

After running for about 5 minutes, at a couple of hundred rpm, the reading is down to 287 ohms...

I've sent a query to TEC, but does anyone have an idea what's going on.

Neil

Hi Geoff,

Tachometers are just toys

Mine was unplugged for about a year... I didn't miss it.

Seriously, they can be a boon for beginners, until they get a feel for the lathe and ho its cutting.

Neil

BUMP!

Bill Perrett of Southampton DMES wrote a history of 25 years of model railway passenger car development. It appeared in Model Engineer between December 1987 and July 1988.

Thanks to the efforts of 'Lofty' the series is now available to subscribers HERE.

Neil

At last! New control box fitted and inverter reprogrammed.

From top to bottom...

Tacho on wall.

Inverter shows amps drawn by motor.

Control box with, on top, stop, start, fwd/off/rev and E-stop. Stop slows over 6 seconds, E-stop cuts the power straight away (via inverter).

Front of control box, power LED (not yet wired in), Speed control (when set to 0 inverter goes into jog mode), 0-100% power meter.

Bottom left is lever for crude leadscrew clutch.

Neil

More seriously, you can get special sticks for welding cast iron (e.g. repairing gearbox flanges), surely that's the stuff you'd use?

Neil

J B Weld?

Neil

I figured it was a throwaway comment, but I couldn't resist

Neil

Hate to upset you, but your 30-bob belt on decimalisation in 1971 would now cost £18.52 if things had kept up with inflation, so it's actually half the price!

Neil

Hi Stephen,

What sort of projects are you looking at? The books I mentioned give a basic introduction to interfacing with and using 'logic' chips, but don't go into great detail. In practice there are three areas you might get into:

Basic logic gates (TTL/CMOS) these days very few people use these beasts unless they have to, but some time playing around with them is worth the effort as one day sticking a NAND gate or flip-flop into a circuit might save you a huge re-design.

'Bespoke' logic chips from simple counters to complex display drivers. For these you generally just need to know the rules for wiring them up (in Mike Tooley's book) and follow the example circuits in the datasheet -usually there's enough there for you to use them as building blocks. You may often find that to 'work' these chips you need:

Microprocessors - the computer on a chip, which is 'where it's at' these days.

The best way into microprocessors isn't a book, it's buying a simple project board, such as an Arduino, for which there will be masses of free tools, support and tutorials on the web, and start playing.

You can dive straight in with micros, but learning about discrete devices and other types of chip will be a big plus when you want your projects to interface with the 'real world'.

Neil

(There are other things like FPGAs, but life's too short, sadly).

Programmed my inverter to show rpm based on drive frequency. Agrees pretty closely with the tachometer.

Hi Clive,

I was going to suggest gentle heat, but you got there in the end.

Neil

Edited By Neil Wyatt on 29/05/2014 21:53:17

A new definition of 'superbike'? Mind you, 200mpg...

**LINK**

Neil

Just to clarify a point, the 'private correspondence' with me did ask me to raise the matter with Diane.

Neil

He's building a full size V1?!!

Neil

Reg,

Ask your good lady to show you where the <Caps Lock> button is...

neil

> I would not for anything be the editor of a small publication again these days.

You should try being a Forum Moderator...

:-/

Neil

'Correlation does not imply causality'... or does it?

Neil

Made a smaller poly-v pulley to go with the big one, give about 40-1200 rpm, which is probably more useful for general stuff. Swapping over takes less than two minutes: loosen off tension screw, lift motor to loosen belt, swap pulleys, and retighten screw.

Although the motor drops lower with eth smaller pulley to get the tension, because the belt angle changes it doesn''t run any nearer the tumbler lever, which is a relief.

The guard went back on a treat after chopping out a rectangular section - it's main job is holding the tacho sensor in place!

Final task (for now) is replacing my pendant with fixed controls built into the old control box. I've now got a clear run for the control cable.

Neil

Looks exactly like the overflow pipe I pulled out of our bathroom. Galvanised and until I got it ought I thought it was lead. I did manage to bend it, just. I haven't tried machining it yet.

Neil